package com.ecloud.common.util;

import com.alibaba.fastjson.JSONObject;
import com.ecloud.common.ResultEnum;
import com.ecloud.common.exception.ServerException;
import com.ecloud.common.standard.InnerHeader;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.util.MultiValueMap;
import org.springframework.web.client.RestTemplate;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.URL;
import java.net.URLConnection;

/**
 * @author Squbi
 */
public class RequestUtil {
    private RequestUtil() {
    }

    public static <T> T templatePost(RestTemplate restTemplate, String url, MultiValueMap<String, String> map, Class<T> resultType) {
        return templatePost(restTemplate, url, map, resultType, headers -> headers);
    }

    public static <T> T templatePost(RestTemplate restTemplate, String url, MultiValueMap<String, String> map, Class<T> resultType, InnerHeader innerHeader) {
        HttpHeaders headers = new HttpHeaders();
        headers.setContentType(MediaType.APPLICATION_JSON);
        headers = innerHeader.setHeader(headers);
        HttpEntity<Object> entity = new HttpEntity<>(map, headers);
        return restTemplate.postForObject(url, entity, resultType);
    }


    /**
     * 向指定 URL 发送POST方法的请求
     *
     * @param url   发送请求的 URL
     * @param param 请求参数，请求参数应该是 name1=value1&name2=value2 的形式。
     * @return 所代表远程资源的响应结果
     */
    public static String sendPost(String url, JSONObject param) {
        PrintWriter out;
        BufferedReader in;
        StringBuilder result = new StringBuilder();
        try {
            URL realUrl = new URL(url);
            // 打开和URL之间的连接
            URLConnection conn = realUrl.openConnection();
            // 设置通用的请求属性
            conn.setRequestProperty("accept", "*/*");
            conn.setRequestProperty("connection", "Keep-Alive");
            conn.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
            conn.setRequestProperty("Content-Type", "application/json; charset=utf-8");
            // 发送POST请求必须设置如下两行
            conn.setDoOutput(true);
            conn.setDoInput(true);
            // 获取URLConnection对象对应的输出流
            out = new PrintWriter(conn.getOutputStream());
            // 发送请求参数
            out.print(param);
            // flush输出流的缓冲
            out.flush();
            // 定义BufferedReader输入流来读取URL的响应
            in = new BufferedReader(
                    new InputStreamReader(conn.getInputStream()));
            String line;
            while ((line = in.readLine()) != null) {
                result.append(line);
            }
        } catch (Exception e) {
            e.printStackTrace();
            throw new ServerException(ResultEnum.CALL_ERROR);
        }
        try {
            out.close();
            in.close();
        } catch (IOException ex) {
            ex.printStackTrace();
        }
        return result.toString();
    }
}

